Roosevelt Reservoir dam
Roosevelt Reservoir
Roosevelt Reservoir, also known as Green Lake Reservoir, is a vital water resource located within Seattle City Limits in King County, Washington. Managed by the Washington Department of Ecology, this local government-owned reservoir was completed in 1910 for the primary purpose of water supply. With a maximum storage capacity of 181 acre-feet and a normal storage capacity of 153 acre-feet, the reservoir covers an area of 8.4 acres and serves as a crucial source of water for the surrounding area.
The dam at Roosevelt Reservoir is of Earth type, with a hydraulic height of 23 feet and a structural height of 23 feet. The reservoir has a high hazard potential but is currently in satisfactory condition, as assessed in April 2021. With a drainage area of 0.01 square miles and a maximum discharge of 45 cubic feet per second, the reservoir plays a key role in managing water resources in the region. Regular inspections are conducted every five years to ensure the safety and functionality of the dam, demonstrating a commitment to proper maintenance and risk management.
As a significant component of the water infrastructure in the area, Roosevelt Reservoir not only provides essential water supply but also contributes to the overall management of water resources in the region. With its strategic location and high hazard potential, the reservoir serves as a critical asset for the community and underscores the importance of effective regulation, inspection, and maintenance practices to ensure the safety and reliability of the water supply system in King County, Washington.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Roosevelt Reservoir -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Thornton Creek Near Seattle | 41 cfs | → |
| Mercer Creek Near Bellevue | 12 cfs | → |
| Duwamish River At Golf Course At Tukwila | 6,700 cfs | → |
| Cedar River At Renton | 335 cfs | → |
| Issaquah Creek Near Mouth Near Issaquah | 34 cfs | → |
| Snohomish River Near Monroe | 4,030 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Roosevelt Reservoir.
Boat launches
- Spu Public Boat Launch
- 14th Avenue Northwest Seattle
- West Galer Street 3121, Seattle
- Beach Drive Northeast 17218, Lake Forest Park
- 68th Avenue Northeast 17181-17299, Kenmore
- Stan Sayres Boat Launch
Campgrounds
- Fay Bainbridge State Park
- Fay Bainbridge State Park Campsite
- Cascadia Marine Trail
- Manchester State Park
- Manchester State Park Campground
- Wwta Campsite (Human Powered Boats Only)
Paddle runs
- Snoqualmie Falls To Plum's Landing
- Confluence With Taylor River To Confluence With North Fork Snoqualmie River
- Wagner Bridge To Confluence With Middle Fork Snoqualmie River
- Brothers Wilderness Boundary To Olympic Nf Boundary
- Headwaters In Ne1/4 Of Sec 14, T29n, R10e To Confluence With Canyon Creek
- Olympic Nf/Olympic Np Bounary To Brothers Wilderness Boundary
Track Roosevelt Reservoir in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Roosevelt Reservoir
Where does the data for Roosevelt Reservoir come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the High hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Roosevelt Reservoir.